DRAFT/PROPOSED. AIR EMISSION PERMIT NO Total Facility Operating Permit Reissuance IS ISSUED TO. Hutchinson Utilities Commission

DRAFT/PROPOSED AIR EMISSION PERMIT NO. 08500034 002 Total Facility Operating Permit Reissuance IS ISSUED TO Hutchinson Utilities Commission Hutchinson Utilities Commission Plant 2 1100 Industrial Boulevard Hutchinson, McLeod County, MN 55350 The emission units, control equipment and emission stacks at the stationary source authorized in this permit reissuance are as described in the Permit Applications Table. This permit reissuance supersedes Air Emission Permit No. 08500034 001 and authorizes the Permittee to operate the stationary source at the address listed above unless otherwise noted in Table A. The Permittee must comply with all the conditions of the permit. Any changes or modifications to the stationary source must be performed in compliance with Minn. R. 7007.1150 to 7007.1500. Terms used in the permit are as defined in the state air pollution control rules unless the term is explicitly defined in the permit. Unless otherwise indicated, all the Minnesota rules cited as the origin of the permit terms are incorporated into the SIP under 40 CFR 52.1220 and as such as are enforceable by U.S. Environmental Protection Agency (EPA) Administrator or citizens under the Clean Air Act. Permit Type: Federal; Part 70/Limits to Avoid NSR Operating Permit Issue Date: <issue date> Expiration Date: <expiration date or Non Expiring> All Title I Conditions do not expire. Don A. Smith, Manager Air Quality Permits Section Industrial Division for John Stine Commissioner Minnesota Pollution Control Agency Permit Applications Table Permit Type Application Date Permit Action Total Facility Operating Permit Reissuance May 4, 2005 002 XX:xx TDD (for hearing and speech impaired only): (651) 282 5332 Printed on recycled paper containing at least 10% fibers from paper recycled by consumers

TABLE OF CONTENTS Notice to the Permittee Permit Shield Facility Description Table A: Limits and Other Requirements Table B: Submittals Table C: not used in this permit Appendix A: not used in this permit Appendix B: Emission factors for GP002 Calculations Appendix C: Insignificant Activities Appendix D: Acid Rain Application

NOTICE TO THE PERMITTEE: Your stationary source may be subject to the requirements of the Minnesota Pollution Control Agency s (MPCA) solid waste, hazardous waste, and water quality programs. If you wish to obtain information on these programs, including information on obtaining any required permits, please contact the MPCA general information number at: Metro Area (651) 296 6300 Outside Metro Area 1 800 657 3864 TTY (651) 282 5332 The rules governing these programs are contained in Minn. R. chs. 7000 7105. Written questions may be sent to: Minnesota Pollution Control Agency, 520 Lafayette Road North, St. Paul, Minnesota 55155 4194. Questions about this air emission permit or about air quality requirements can also be directed to the telephone numbers and address listed above. PERMIT SHIELD: Subject to the limitations in Minn. R. 7007.1800, compliance with the conditions of this permit shall be deemed compliance with the specific provision of the applicable requirement identified in the permit as the basis of each condition. Subject to the limitations of Minn. R. 7007.1800 and 7017.0100, subp. 2, notwithstanding the conditions of this permit specifying compliance practices for applicable requirements, any person (including the Permittee) may also use other credible evidence to establish compliance or noncompliance with applicable requirements. FACILITY DESCRIPTION: Hutchinson Utilities Commission (HUC) Plant 2 is an existing municipal electric generation utility located at 1100 Industrial Boulevard, Hutchinson, Minnesota. The primary responsibility of HUC is to provide electrical power to the City of Hutchinson. HUC purchases some of its power from other sources, and produces its own power when: 1) their contracted power supplier requests them to generate; 2) power is interrupted; or 3) economical power is not available through MidContinent Area Power Pool. Emission units at the facility include a GE LM 6000 52 megawatt (MW) combined cycle combustion turbine restricted to combusting natural gas (EU001) and a GE Frame 5 22 megawatt (MW) simple cycle combustion turbine restricted to combusting natural gas (EU004) and one steam boiler that combusts natural gas (EU003). HUC uses water injection to control NO X emissions from the two turbines. Because the combined cycle combustion turbine uses a recovered heat steam boiler to power an additional generator, HUC is considered one of the 28 named source categories listed in 40 CFR 52.21, making its major source threshold for New Source Review 100 tons per year. The facility was previously considered and remains a non major source for New Source Review (NSR) through federally enforceable synthetic minor limits of 99 tons per year NO X and CO, along with the requirement to operate air pollution control equipment. This stationary source is located in an area which is designated attainment (or unclassifiable) for all criteria pollutants. Limitation of the remaining criteria pollutants is not required, since the potential emissions of all other regulated pollutants are under major source thresholds listed in 40 CFR 52.21. TDD (for hearing and speech impaired only): (651) 282 5332 Printed on recycled paper containing at least 10% fibers from paper recycled by consumers

TABLE A: LIMITS AND OTHER REQUIREMENTS Facility Name: Hutchinson Utilities Commission -Plant 2 Permit Number: 08500034-002 A-1 Table A contains limits and other requirements with which your facility must comply. The limits are located in the first column of the table (What To do). The limits can be emission limits or operational limits. This column also contains the actions that you must take and the records you must keep to show that you are complying with the limits. The second column of Table A (Why to do it) lists the regulatory basis for these limits. Appendices included as conditions of your permit are listed in Table A under total facility requirements. Subject Item: Total Facility What to do SOURCE-SPECIFIC REQUIREMENTS Acid Rain Program: This source is subject to U.S. EPA's Acid Rain Program pursuant to the requirements in 40 CFR Parts 72, 73, 75, 77 and 78. Certain Acid Rain Program requirements are included in Tables A and/or B of this permit for the purpose tracking by the MPCA. All other Acid Rain Program requirements are referenced in the Phase II Permit Application attached to this permit as Appendix A. Permit Appendices: This permit contains appendices as listed in the permit Table of Contents. The Permittee shall comply with all requirements contained in the appendices. This permit establishes limits on the facility to keep it a minor source under New Source Review. The Permittee cannot make any change at the source that would make the source a major source under New Source Review until a permit amendment has been issued. This includes changes that might otherwise qualify as insignificant modifications and minor or moderate amendments. OPERATIONAL REQUIREMENTS The Permittee shall comply with National Primary and Secondary Ambient Air Quality Standards, 40 CFR pt. 50, and the Minnesota Ambient Air Quality Standards, Minn. R. 7009.0010 to 7009.0080. Compliance shall be demonstrated upon written request by the MPCA. Circumvention: Do not install or use a device or means that conceals or dilutes emissions, which would otherwise violate a federal or state air pollution control rule, without reducing the total amount of pollutant emitted. Air Pollution Control Equipment: Operate all pollution control equipment whenever the corresponding process equipment and emission units are operated. Operation and Maintenance Plan: Retain at the stationary source an operation and maintenance plan for all air pollution control equipment. At a minimum, the O & M plan shall identify all air pollution control equipment and control practices and shall include a preventative maintenance program for the equipment and practices, a description of (the minimum but not necessarily the only) corrective actions to be taken to restore the equipment and practices to proper operation to meet applicable permit conditions, a description of the employee training program for proper operation and maintenance of the control equipment and practices, and the records kept to demonstrate plan implementation. Operation Changes: In any shutdown, breakdown, or deviation the Permittee shall immediately take all practical steps to modify operations to reduce the emission of any regulated air pollutant. The Commissioner may require feasible and practical modifications in the operation to reduce emissions of air pollutants. No emissions units that have an unreasonable shutdown or breakdown frequency of process or control equipment shall be permitted to operate. Fugitive Emissions: Do not cause or permit the handling, use, transporting, or storage of any material in a manner which may allow avoidable amounts of particulate matter to become airborne. Comply with all other requirements listed in Minn. R. 7011.0150. Noise: The Permittee shall comply with the noise standards set forth in Minn. R. 7030.0010 to 7030.0080 at all times during the operation of any emission units. This is a state only requirement and is not enforceable by the EPA Administrator or citizens under the Clean Air Act. Inspections: The Permittee shall comply with the inspection procedures and requirements as found in Minn. R. 7007.0800, subp. 9(A). The Permittee shall comply with the General Conditions listed in Minn. R. 7007.0800, subp. 16. PERFORMANCE TESTING Performance Testing: Conduct all performance tests in accordance with Minn. R. ch. 7017 unless otherwise noted in Tables A and/or B. Why to do it 40 CFR Section 72.6(a)(3)(i); 40 CFR Section 72.9; 40 CFR Section 72.30(b)(2)(ii); Minn. R. 7007.1075 Minn. R. 7007.0800, subp. 2 Title I Condition: To avoid classification as a major source and modification under 40 CFR Section 52.21 and Minn. R. 7007.3000 40 CFR pt. 50; Minn. Stat. Section 116.07, subds. 4a & 9; Minn. R. 7007.0100, subp. 7(A), 7(L), & 7(M); Minn. R. 7007.0800, subps. 1, 2 & 4; Minn. R. 7009.0010-7009.0080 Minn. R. 7011.0020 Minn. R. 7007.0800, subp. 2; Minn. R. 7007.0800, subp. 16(J) Minn. R. 7007.0800, subps. 14 and 16(J) Minn. R. 7019.1000, subp. 4 Minn. R. 7011.0150 Minn. R. 7030.0010-7030.0080 Minn. R. 7007.0800, subp. 9(A) Minn. R. 7007.0800, subp. 16 Minn. R. ch. 7017

TABLE A: LIMITS AND OTHER REQUIREMENTS Facility Name: Hutchinson Utilities Commission -Plant 2 Permit Number: 08500034-002 A-2 Performance Test Notifications and Submittals: Performance Tests are due as outlined in Table A of the permit. See Table B for additional testing requirements. Minn. R. 7017.2018; Minn. R. 7017.2030, subps. 1-4, Minn. R. 7017.2035, subps. 1-2 Performance Test Notification (written): due 30 days before each Performance Test Performance Test Plan: due 30 days before each Performance Test Performance Test Pre-test Meeting: due 7 days before each Performance Test Performance Test Report: due 45 days after each Performance Test Performance Test Report - Microfiche Copy: due 105 days after each Performance Test The Notification, Test Plan, and Test Report may be submitted in an alternative format as allowed by Minn. R. 7017.2018. Limits set as a result of a performance test (conducted before or after permit issuance) apply until superseded as stated in the MPCA's Notice of Compliance letter granting preliminary approval. Preliminary approval is based on formal review of a subsequent performance test on the same unit as specified by Minn. R. 7017.2025, subp. 3. The limit is final upon issuance of a permit amendment incorporating the change. MONITORING REQUIREMENTS Monitoring Equipment Calibration: The Permittee shall calibrate all required monitoring equipment at least once every 12 months (any requirements applying to continuous emission monitors are listed separately in this permit). Operation of Monitoring Equipment: Unless otherwise noted in Tables A, B, and/or C, monitoring a process or control equipment connected to that process is not necessary during periods when the process is shutdown, or during checks of the monitoring systems, such as calibration checks and zero and span adjustments. If monitoring records are required, they should reflect any such periods of process shutdown or checks of the monitoring system. RECORDKEEPING Recordkeeping: Retain all records at the stationary source, unless otherwise specified within this permit, for a period of five (5) years from the date of monitoring, sample, measurement, or report. Records which must be retained at this location include all calibration and maintenance records, all original recordings for continuous monitoring instrumentation, and copies of all reports required by the permit. Records must conform to the requirements listed in Minn. R. 7007.0800, subp. 5(A). Recordkeeping: Maintain records describing any insignificant modifications (as required by Minn. R. 7007.1250, subp. 3) or changes contravening permit terms (as required by Minn. R. 7007.1350, subp. 2), including records of the emissions resulting from those changes. If the Permittee determines that no permit amendment or notification is required prior to making a change, the Permittee must retain records of all calculations required under Minn. R. 7007.1200. These records shall be kept for a period of five years from the date the change was made or until permit reissuance, whichever is longer. The records shall be kept at the stationary source for the current calendar year of operation and may be kept at the stationary source or office of the stationary source for all other years. The records may be maintained in either electronic or paper format. REPORTING/SUBMITTALS Shutdown Notifications: Notify the Commissioner at least 24 hours in advance of a planned shutdown of any control equipment or process equipment if the shutdown would cause any increase in the emissions of any regulated air pollutant. If the owner or operator does not have advance knowledge of the shutdown, notification shall be made to the Commissioner as soon as possible after the shutdown. However, notification is not required in the circumstances outlined in Items A, B and C of Minn. R. 7019.1000, subp. 3. At the time of notification, the owner or operator shall inform the Commissioner of the cause of the shutdown and the estimated duration. The owner or operator shall notify the Commissioner when the shutdown is over. Minn. R. 7017.2025, subp. 3 Minn. R. 7007.0800, subp. 4(D) Minn. R. 7007.0800, subp. 4(D) Minn. R. 7007.0800, subp. 5(C) Minn. R. 7007.0800, subp. 5(B) Minn. R. 7007.1200, subp. 4 Minn. R. 7019.1000, subp. 3

TABLE A: LIMITS AND OTHER REQUIREMENTS Facility Name: Hutchinson Utilities Commission -Plant 2 Permit Number: 08500034-002 A-3 Breakdown Notifications: Notify the Commissioner within 24 hours of a breakdown of more than one hour duration of any control equipment or process equipment if the breakdown causes any increase in the emissions of any regulated air pollutant. The 24-hour time period starts when the breakdown was discovered or reasonably should have been discovered by the owner or operator. However, notification is not required in the circumstances outlined in Items A, B and C of Minn. R. 7019.1000, subp. 2. Minn. R. 7019.1000, subp. 2 At the time of notification or as soon as possible thereafter, the owner or operator shall inform the Commissioner of the cause of the breakdown and the estimated duration. The owner or operator shall notify the Commissioner when the breakdown is over. Notification of Deviations Endangering Human Health or the Environment: As soon Minn. R. 7019.1000, subp. 1 as possible after discovery, notify the Commissioner or the state duty officer, either orally or by facsimile, of any deviation from permit conditions which could endanger human health or the environment. Notification of Deviations Endangering Human Health or the Environment Report: Minn. R. 7019.1000, subp. 1 Within 2 working days of discovery, notify the Commissioner in writing of any deviation from permit conditions which could endanger human health or the environment. Include the following information in this written description: 1. the cause of the deviation; 2. the exact dates of the period of the deviation, if the deviation has been corrected; 3. whether or not the deviation has been corrected; 4. the anticipated time by which the deviation is expected to be corrected, if not yet corrected; and 5. steps taken or planned to reduce, eliminate, and prevent reoccurrence of the deviation. Application for Permit Amendment: If a permit amendment is needed, submit an Minn. R. 7007.1150-7007.1500 application in accordance with the requirements of Minn. R. 7007.1150 through Minn. R. 7007.1500. Submittal dates vary, depending on the type of amendment needed. Extension Requests: The Permittee may apply for an Administrative Amendment to Minn. R. 7007.1400, subp. 1(H) extend a deadline in a permit by no more than 120 days, provided the proposed deadline extension meets the requirements of Minn. R. 7007.1400, subp. 1(H). Performance testing deadlines from the General Provisions of 40 CFR pt. 60 and pt. 63 are examples of deadlines for which the MPCA does not have authority to grant extensions and therefore do not meet the requirements of Minn. R. 7007.1400, subp. 1(H). Emission Inventory Report: due on or before April 1 of each calendar year following Minn. R. 7019.3000-7019.3100 permit issuance, to be submitted on a form approved by the Commissioner. Emission Fees: due 60 days after receipt of an MPCA bill. Minn. R. 7002.0005-7002.0095

TABLE A: LIMITS AND OTHER REQUIREMENTS Facility Name: Hutchinson Utilities Commission -Plant 2 Permit Number: 08500034-002 A-4 Subject Item: Associated Items: GP 002 NOX and CO limits EU 001 Main turbine, single and combined cycles EU 003 Combustion Air Preheat Boiler EU 004 Peaking turbine What to do A. EMISSION LIMITS Nitrogen Oxides: less than or equal to 95.0 tons/year using 12-month Rolling Sum calculated using Equation 1, found in Appendix B of this permit. The intent is that data from MR001 is used for EU001, published emission factors from AP-42 are used for EU003, and Performance-Test-Based emission factors as described below and in Appendix B are used for EU004. Carbon Monoxide: less than or equal to 95.0 tons/year using 12-month Rolling Sum calculated using Equation 2, found in Appendix B of this permit. The intent is that published emission factors from AP-42 are used for EU003, and Performance-Test-Based emission factors as described below and in Appendix B are used for EU001 and EU004. Monthly Records: By the 15th day of each month, calculate and record: -- The monthly NOX emissions from units included in GP002, using Equation 1 Why to do it Title I Condition: To avoid classification as a major source and modification under 40 CFR Section 52.21 and Minn. R. 7007.3000 Title I Condition: To avoid classification as a major source and modification under 40 CFR Section 52.21 and Minn. R. 7007.3000 Title I Condition: To avoid classification as a major source and modification under 40 CFR Section 52.21 and Minn. R. 7007.3000 -- The 12-month rolling sum of NOX emissions, by adding the calculated monthly NOX emissions for the previous 12 months. Monthly Records: By the 15th day of each month, calculate and record: -- The monthly CO emissions from units included in GP002, using Equation 2 -- The 12-month rolling sum of CO emissions, by adding the calculated monthly CO emissions for the previous 12 months. Use of Performance-Test-Based NOX and CO Emission Factors: All CO and NOX emission factors based on performance testing shall be revised based on the results of each performance test. The Permittee shall use the most-recent performance test-revised emission factor for calculating CO and NOX emissions. Title I Condition: To avoid classification as a major source and modification under 40 CFR Section 52.21 and Minn. R. 7007.3000 Title I Condition: To avoid classification as a major source and modification under 40 CFR Section 52.21 and Minn. R. 7007.3000 The use of the updated emission factors shall commence upon rececipt of written notification from the MPCA that the performance testing results were valid.

TABLE A: LIMITS AND OTHER REQUIREMENTS Facility Name: Permit Number: Hutchinson Utilities Commission -Plant 2 08500034-002 Subject Item: EU 001 Main turbine, single and combined cycles A-5 Associated Items: CE 001 Steam or Water Injection GP 002 NOX and CO limits MR 001 NOX monitor MR 002 CO2 monitor SV 001 Main Turbine Primary Stack SV 002 Main Turbine Bypass stack What to do EMISSION AND OPERATION LIMITS (also see Subject Item GP002 for additional limits applicable to EU001) Nitrogen Oxides: less than or equal to 0.0114 percent by volume using 3-hour Average (114 ppmv) at 15 percent oxygen on a dry basis during simple cycle operation, except when ice fog is deemed a traffic hazard by the owner or operator of the gas turbine. This limit applies at SV001 after start-up and during normal operating conditions. Nitrogen Oxides: less than or equal to 0.0141 percent by volume using 3-hour Average (141 ppmv) at 15 percent oxygen on a dry basis during combined cycle operation, except when ice fog is deemed a traffic hazard by the owner or operator of the gas turbine. This limit applies at SV001 after start-up and during normal operating conditions. Opacity: less than or equal to 20 percent opacity using 6-minute Average once operating temperatures have been attained. This limit applies to both SV 001 and SV 002. Sulfur Dioxide: less than or equal to 0.5 lbs/million Btu heat input using 3-hour Average. Potential emissions based on the allowed fuel (pipeline natural gas) and equipment capacity are approximately 0.003 lb/mmbtu heat input. Fuel Use: pipeline quality natural gas only. Sulfur Content of Fuel: less than or equal to 0.8 percent by volume. This is met through the combustion of only pipeline natural gas; documentation is required as described below. ACID RAIN PROGRAM REQUIREMENTS Comply with all acid rain requirements. These are included here and in Appendix B of the permit. Emissions from the stationary source cannot exceed any allowances that the source lawfully holds under federal acid rain regulations, except as allowed by Minn. R. 7007.0800, subp. 7. Acid Rain Certification Report: due 60 days after end of each calendar year starting January 1, 2000 If the unit has excess emissions, the designated representative shall submit a proposed offset plan in accordance with 40 CFR Section 72.9(e). Keep the certificate of representation, all emissions monitoring information, copies of all reports, compliance certifications and related submissions and all records made or required under the Acid Rain Program on site for a period of 5 years from the date the document was created. Hold allowances after January 1, 2001, as of the allowance transfer deadline, in the unit's compliance subaccount. Allowances may not be less than the total annual emissions of sulfur dioxide from the previous calendar year from the unit. Certify Acid Rain Program Submittals: Each submission under the Acid Rain Program shall be submitted, signed, and certified by the designated representative for all sources on behalf of which the submission is made in accordance with 40 CFR Section 72.21. CONTROL EQUIPMENT REQUIREMENTS (see also Subject Item CE001) The Permittee shall operate and maintain CE001 any time that EU001 is in operation, except as allowed under 40 CFR Section 60.332(f). when ice fog is deemed a traffic hazard by the owner or operator of the gas turbine. The Permittee shall document periods of non-operation of the control equipment. Water Injection System Deactivation: Report to the Administrator each period where the water injection system is deactivated due to ice fog conditions. The report shall include the date and time the system is deactivated and reactivated, along with the ambient weather conditions. Why to do it 40 CFR Section 60.332(a)(1); 40 CFR Section 60.332(b); 40 CFR Section 60.332(f); Minn. R. 7011.2350 40 CFR Section 60.332(a)(1); 40 CFR Section 60.332(b); 40 CFR Section 60.332(f); Minn. R. 7011.2350 Minn. R. 7011.2300, subp. 1 Minn. R. 7011.2300, subp. 2 Minn. R. 7005.0100, subp. 35a 40 CFR Section 60.333(b); Minn. R. 7011.2350 40 CFR pts. 72, 73, 75 and 76; Minn. R. 7007.1075 Minn. R. 7007.0800, subp. 7 40 CFR Section 72.90(b) and 40 CFR Section 72.90(c); Minn. R. 7007.1075 40 CFR Section 72.9(e); Minn. R. 7007.1075 40 CFR Section 72.9(f); Minn. R. 7007.1075 40 CFR Section 72.9(c); Minn. R. 7007.1075 40 CFR Section 72.21; Minn. R. 7007.1075 Title I Condition: To avoid classification as a major source and modification under 40 CFR Section 52.21 and Minn. R. 7007.3000 40 CFR Section 60.334(h)(3); Minn. R. 7011.2350

TABLE A: LIMITS AND OTHER REQUIREMENTS Facility Name: Hutchinson Utilities Commission -Plant 2 Permit Number: 08500034-002 A-6 MONITORING REQUIREMENTS (see also Subject Item MR001) Emissions Monitoring: The owner or operator shall use an in-stack CEMS to measure NOx emissions for EU001 in accordance with 40 CFR Section 75.10. The emissions data collected by the NOX CEMS shall also be used when calculating the NOX emissions pursuant to the limit found at GP002. RECORDKEEPING REQUIREMENTS Maintain documentation of the gas quality characteristics in a current, valid purchase contract, tariff sheet or transportation contract for the gaseous fuel, specifying that the maximum total sulfur content of the fuel is 20.0 grains/100 scf or less. Maintain records of the occurrence and duration of any start-up, shutdown, or malfunction in the operation of an affected facility; any malfunction of the air pollution control equipment, or any periods during which a continuous monitoring system or monitoring device is inoperative. Maintain a file of all measurements, including continuous monitoring system, monitoring device, and performance test measurements; all continuous monitoring system performance evaluations; all continuous monitoring system or monitoring device calibration checks; adjustments and maintenance performed on these systems or devices; and all other information required, recorded in a permanent form suitable for inspection. The file shall be retained for a minimum of two years following the date of such measurements, maintenance, reports and records. Recordkeeping - CEMS Data: Retain records of all CEMS monitoring data and support information for a period of five years from the date of the monitoring sample, measurement or report. Records are to be kept at the source. Daily Recordkeeping: Each day, record the heat input to EU001, in million Btu (MMBtu), while the water injection system is operating. Daily Recordkeeping: Each day, record the heat input to EU001, in million Btu (MMBtu), while the water injection system is not operating. On any given day when the water injection system was operated at all times (i.e., there was no heat input during non-operation of the water injection system), no record is required. Monthly Recordkeeping: By the 15th day of each month, calculate and record the total MMBtu heat input to EU001 while the water-injection system was operating. This is Q1 for use in calculations described in GP002. Monthly Recordkeeping: By the 15th day of each month, calculate and record the total MMBtu heat input to EU001 while the water-injection system was not operating. This is Q2 for use in calculations described in GP002. For any given month when the water injection system was operated at all times (i.e., there was no heat input during non-operation of the water injection system), no record is required. PERFORMANCE TESTING REQUIREMENTS Performance Test: due before end of each 60 months starting 07/31/2010, to measure CO emissions, not to exceed 60 months between test dates. The CO performance test shall be conducted to verify the emission factor (in lb/mmbtu) used in determining compliance with the GP002 CO limit. Title I Condition: To avoid classification of a previous modification as major under 40 CFR Section 52.21 and Minn. R. 7007.3000; 40 CFR Section 75.10 40 CFR Section 60.334(h)(3)(i); Minn. R. 7011.2350 40 CFR Section 60.7(b); Minn. R. 7019.0100, subp. 1 40 CFR Section 60.7(f); Minn. R. 7019.0100, subp. 1 40 CFR Section 75.50; Minn. R. 7007.0800, subp. 5 Title I Condition: To avoid classification as a major source and modification under 40 CFR Section 52.21 and Minn. R. 7007.3000 Title I Condition: To avoid classification as a major source and modification under 40 CFR Section 52.21 and Minn. R. 7007.3000 Minn. R. 7007.0800, subp. 4 and 5 Minn. R. 7007.0800, subp. 4 and 5 Minn. R. 7017.2020, subp. 1 The next test is due by 4/30/2016.

TABLE A: LIMITS AND OTHER REQUIREMENTS Facility Name: Permit Number: Hutchinson Utilities Commission -Plant 2 08500034-002 Subject Item: EU 003 Combustion Air Preheat Boiler A-7 Associated Items: GP 002 NOX and CO limits SV 003 Combustion Air Preheat Boiler Stack What to do EMISSION LIMITS -- See Subject Item GP002 for limits applicable to EU003 OPERATIONAL REQUIREMENTS Fuel Use: EU003 is restricted to combusting only pipeline quality natural gas. MONITORING AND RECORDKEEPING REQUIREMENTS Daily Recordkeeping: Each day, record the quantity of natural gas combusted in EU003. Monthly Recordkeeping: By the 15th day of each month, calculate and record the total fuel input to EU003 for the previous month. This is Q3 for use in calculations described in GP002. Records of fuel usage required under 40 CFR Section 60.48c(g) shall be maintained by the owner or operator of the affected facility for a period of two years following the date of such record. Why to do it Minn. R. 7005.0100, subp. 35a Title I Condition: To avoid classification as a major source and modification under 40 CFR Section 52.21 and Minn. R. 7007.3000; 40 CFR Section 60.48c(g)(1); Minn. R. 7011.0570 Minn. R. 7007.0800, subp. 4 and 5 40 CFR Section 60.48c(i); Minn. R. 7011.0570

TABLE A: LIMITS AND OTHER REQUIREMENTS Facility Name: Permit Number: Hutchinson Utilities Commission -Plant 2 08500034-002 Subject Item: EU 004 Peaking turbine A-8 Associated Items: CE 002 Steam or Water Injection GP 002 NOX and CO limits SV 004 Peaking Turbine stack What to do EMISSION AND OPERATION LIMITS (also see Subject Item GP002 for additional limits applicable to EU004) Nitrogen Oxides: less than or equal to 0.0075 percent by volume using 3-hour Average (75 ppmv) at 15 percent oxygen on a dry basis, except when ice fog is deemed a traffic hazard by the owner or operator of the gas turbine. This limit applies at SV004 after start-up and during normal operating conditions. Opacity: less than or equal to 20 percent opacity using 6-minute Average once operating temperatures have been attained. Sulfur Dioxide: less than or equal to 0.5 lbs/million Btu heat input using 3-hour Average. Potential emissions based on the allowed fuel (pipeline natural gas) and equipment capacity are approximately 0.003 lb/mmbtu heat input. Fuel Use: pipeline quality natural gas only. Sulfur Content of Fuel: less than or equal to 0.8 percent by volume. This is met through the combustion of only pipeline natural gas; documentation is required as described below. CONTROL EQUIPMENT REQUIREMENTS (see also Subject Item CE002) The Permittee shall operate and maintain CE002 any time that EU004 is in operation, except as allowed under 40 CFR Section 60.332(f). when ice fog is deemed a traffic hazard by the owner or operator of the gas turbine. The Permittee shall document periods of non-operation of the control equipment. Water Injection System Deactivation: Report to the Administrator each period where the water injection system is deactivated due to ice fog conditions. The report shall include the date and time the system is deactivated and reactivated, along with the ambient weather conditions. RECORDKEEPING REQUIREMENTS Maintain documentation of the gas quality characteristics in a current, valid purchase contract, tariff sheet or transportation contract for the gaseous fuel, specifying that the maximum total sulfur content of the fuel is 20.0 grains/100 scf or less. Maintain records of the occurrence and duration of any start-up, shutdown, or malfunction in the operation of an affected facility; any malfunction of the air pollution control equipment, or any periods during which a continuous monitoring system or monitoring device is inoperative. Maintain a file of all measurements, including continuous monitoring system, monitoring device, and performance test measurements; all continuous monitoring system performance evaluations; all continuous monitoring system or monitoring device calibration checks; adjustments and maintenance performed on these systems or devices; and all other information required, recorded in a permanent form suitable for inspection. The file shall be retained for a minimum of two years following the date of such measurements, maintenance, reports and records. Daily Recordkeeping: Each day, record the heat input to EU004, in million Btu (MMBtu), while the water injection system is operating. Daily Recordkeeping: Each day, record the heat input to EU004, in million Btu (MMBtu), while the water injection system is not operating. On any given day when the water injection system was operated at all times (i.e., there was no heat input during non-operation of the water injection system), no record is required. Monthly Recordkeeping: By the 15th day of each month, calculate and record the total MMBtu heat input to EU004 while the water-injection system was operating. This is Q4 for use in calculations described in GP002. Monthly Recordkeeping: By the 15th day of each month, calculate and record the total MMBtu heat input to EU004 while the water-injection system was not operating. This is Q5 for use in calculations described in GP002. Why to do it 40 CFR Section 60.332(a)(1); 40 CFR Section 60.332(b); 40 CFR Section 60.332(f); Minn. R. 7011.2350 Minn. R. 7011.2300, subp. 1 Minn. R. 7011.2300, subp. 2 Minn. R. 7005.0100, subp. 35a 40 CFR Section 60.333(b); Minn. R. 7011.2350 Title I Condition: To avoid classification as a major source and modification under 40 CFR Section 52.21 and Minn. R. 7007.3000 40 CFR Section 60.334(h)(3); Minn. R. 7011.2350 40 CFR Section 60.334(h)(3)(i); Minn. R. 7011.2350 40 CFR Section 60.7(b); Minn. R. 7019.0100, subp. 1 40 CFR Section 60.7(f); Minn. R. 7019.0100, subp. 1 Title I Condition: To avoid classification as a major source and modification under 40 CFR Section 52.21 and Minn. R. 7007.3000 Title I Condition: To avoid classification as a major source and modification under 40 CFR Section 52.21 and Minn. R. 7007.3000 Minn. R. 7007.0800, subp. 4 and 5 Minn. R. 7007.0800, subp. 4 and 5 For any given month when the water injection system was operated at all times (i.e., there was no heat input during non-operation of the water injection system), no record is required.

TABLE A: LIMITS AND OTHER REQUIREMENTS Facility Name: Hutchinson Utilities Commission -Plant 2 Permit Number: 08500034-002 A-9 PERFORMANCE TESTING REQUIREMENTS Performance Test: due before end of each 60 months starting 07/18/2001, to measure NOX emissions, not to exceed 60 months between test dates. The NOX performance test shall be conducted to verify the emission factor (in lb/mmbtu) used in determining compliance with the GP002 NOX limit. The next test is due before 4/30/2016. Performance Test: due before end of each 60 months starting 07/18/2001, to measure CO emissions, not to exceed 60 months between test dates. The CO performance test shall be conducted to verify the emission factor (in lb/mmbtu) used in determining compliance with the GP002 CO limit. Minn. R. 7017.2020, subp. 1 Minn. R. 7017.2020, subp. 1 The next test is due before 4/30/2016.

TABLE A: LIMITS AND OTHER REQUIREMENTS Facility Name: Permit Number: Hutchinson Utilities Commission -Plant 2 08500034-002 Subject Item: CE 001 Steam or Water Injection A-10 Associated Items: EU 001 Main turbine, single and combined cycles What to do The Permittee shall operate and maintain CE001 in accordance with the Operation and Maintenance (O & M) Plan. The Permittee shall keep copies of the O & M Plan available for use by staff and MPCA staff. Continuous Monitoring: The NOX CEMS (MR001) shall be used to assess proper operation of the steam or water injection system. Continuous Monitoring: The Permittee shall continuously monitor and record the NOX emissions in the EU001 exhaust. See Subject Item MR001 for specific CEMS operating requirements. Nitrogen Oxides: less than or equal to 0.42 lbs/million Btu heat input using 1-minute Average. NOX emissions readings in excess of this limit shall be considered an excursion under 40 CFR Section 64.6(c)(2), for purposes of the NOX limits at EU001. Monitoring Equipment: The Permittee shall install and maintain the necessary monitoring equipment for the steam or water injection system as required by this permit. The monitoring equipment must be installed, in use, and properly maintained when EU001 is in operation. Periodic Inspections: At least once per calendar quarter, or more frequently as required by the manufacturing specifications, the Permittee shall inspect the control equipment components. The Permittee shall maintain a written record of these inspections. Corrective Actions: The Permittee shall take corrective action as soon as possible if any of the following occur: Why to do it Minn. R. 7007.0800, subp. 14 40 CFR Section 64.7(a); Minn. R. 7017.0200; 40 CFR Section 60.334(b); Minn. R. 7011.2350 Title I Condition: To avoid classification as a major source and modification under 40 CFR Section 52.21 and Minn. R. 7007.3000; Minn. R. 7007.0800, subps. 2 and 14; 40 CFR Section 64.3(d); Minn. R. 7017.0200 40 CFR Section 64.3; Minn. R. 7017.0200 40 CFR Section 64.7(b); Minn. R. 7017.0200; Minn. R. 7007.0800, subp. 4 40 CFR Section 64.3; Minn. R. 7017.0200 40 CFR Section 64.7(d); Minn. R. 7017.0200 - the NOX CEMS records a data point above the NOX emission limit; or - the water/steam injection system or any of its components are found during the inspections to need repair. Corrective actions shall return the NOX emissions to below the emission limit and/or include completion of necessary repairs identified during the inspection, as applicable. Corrective actions include, but are not limited to, those outlined in the O & M Plan for CE001. The Permittee shall keep a record of the type and date of any corrective action taken. The Permittee shall calibrate the gauges at least once every 12 months and shall maintain a written record of any action resulting from the calibration. Documentation of Need for Improved Monitoring: If the Permittee fails to achieve compliance with an emission limitation or standard for which the monitoring did not provide an indication of an excursion or exceedance while providing valid data, or the results of compliance or performance testing document a need to modify the existing pressure drop range, the Permittee shall promptly notify the MPCA and, if necessary, submit a permit amendment application to address the necessary monitoring change. As required by 40 CFR Section 64.9(a)(2), for the Semi-Annual Deviations Report listed in Table B of this permit and/or the Notification of Deviations Endangering Human Health and the Environment listed earlier in Table A of this permit, as applicable, the Permittee shall include the following related to the monitoring identified as required by 40 CFR pt. 64: 1) Summary information on the number, duration, and cause of excursions or exceedances, as applicable, and the corrective action taken; and 2) Summary information on the number, duration, and cause for monitor downtime incidents. The Permittee shall maintain records of monitoring data, monitor performance data, corrective actions taken, and other supporting information required to be maintained. The Permittee may maintain records on alternative media, such as microfilm, computer files, magnetic tape disks, or microfiche, provided that the use of such alternative media allows for expeditious inspection and review, and does not conflict with other applicable recordkeeping requirements. 40 CFR Section 64.3; Minn. R. 7017.0200 40 CFR Section 64.7(e); Minn. R. 7017.0200 40 CFR Section 64.9(a)(2); Minn. R. 7017.0200 40 CFR Section 64.9(b); Minn. R. 7017.0200

TABLE A: LIMITS AND OTHER REQUIREMENTS Facility Name: Permit Number: Hutchinson Utilities Commission -Plant 2 08500034-002 Subject Item: CE 002 Steam or Water Injection A-11 Associated Items: EU 004 Peaking turbine What to do The Permittee shall operate and maintain CE002 in accordance with the Operation and Maintenance (O & M) Plan. The Permittee shall keep copies of the O & M Plan available for use by staff and MPCA staff. Install and operate a continuous monitoring system to monitor and record the ratio of water and fuel consumption, accurate to within +/- 5%. This is accomplished through a computer operating system for the turbine, which is programmed to alert the operator of issues with the water injection rate. Monitoring Equipment: The Permittee shall install and maintain the necessary monitoring equipment for measuring and recording water/steam injection rate as required by this permit. The monitoring equipment must be installed, in use, and properly maintained when the system is in operation. Periodic Inspections: At least once per calendar quarter, or more frequently as required by the manufacturing specifications, the Permittee shall inspect the control equipment components. The Permittee shall maintain a written record of these inspections. Corrective Actions: The Permittee shall take corrective action as soon as possible if any of the following occur: Why to do it Minn. R. 7007.0800, subp. 14 40 CFR Section 60.334(a); Minn. R. 7011.2350 Minn. R. 7007.0800, subp. 4 Minn. R. 7007.0800, subps. 4, 5 and 14 Minn. R. 7007.0800, subps. 4, 5, and 14 - the recorded water/steam-to-fuel injection ratio is outside the required operating range; or - any of the system components are found during the inspections to need repair. Corrective actions shall return the water/steam-to-fuel injection ratio to within the permitted range, and/or include completion of necessary repairs identified during the inspection, as applicable. Corrective actions include, but are not limited to, those outlined in the O & M Plan for CE002. The Permittee shall keep a record of the type and date of any corrective action taken for CE002.

TABLE A: LIMITS AND OTHER REQUIREMENTS Facility Name: Hutchinson Utilities Commission -Plant 2 Permit Number: 08500034-002 A-12 Subject Item: Associated Items: MR 001 NOX monitor CM 001 Acid Rain Monitoring EU 001 Main turbine, single and combined cycles What to do The CEMS/COMS requirements listed below outline the typical standards of 40 CFR Pt. 75. Additional monitoring requirements may also apply to the Facility based on the standard and it is the responsibility of the Facility to meet all applicable requirements. Certification Application: The owner or operator shall apply for certification of each continuous emission or opacity monitoring system used under the Acid Rain Program. The owner or operator shall submit the certification application in accordance with 40 CFR Section 75.60 and each complete certification application shall include the information specified in Section 75.63. Monitoring Data: Hourly averages shall be computed using at least one data point in each fifteen minute quadrant of an hour, where the unit combusted fuel during that quadrant of an hour. Not withstanding this requirement, an hourly average may be computed from at least two data points separated by a minimum of 15 minutes (where the unit operates for more than one quadrant of an hour) if data is unavailable as a result of the performance of calibration, quality assurance, or preventive maintenance activities pursuant to 40 CFR Section 75.21 and appendix B of pt. 75, or backups of data from the data acquisition and handling system, or recertification, pursuant to Section 75.20. The owner or operator shall use all valid measurements or data points collected during an hour to calculate the hourly averages. All data points collected during an hour shall be, to the extent practicable, evenly spaced over the hour. CEMS QA/QC: The owner or operator of an affected facility shall operate, calibrate, and maintain each CEMS according to the QA/QC procedures in 40 CFR pt. 75, Appendix B as amended. QA Plan: Develop and implement a written plan that describes in detail (or that refers to separate documents containing) complete, step-by-step procedures and operations of the activities outlined in 40 CFR pt. 75, Appendix B, Section 1.1. Upon request from regulatory authorities, the source shall make all procedures, maintenance records, and ancillary supporting documentation from the manufacturer (e.g., software coefficients and troubleshooting diagrams) available for review during an audit. Electronic storage of the information in the QA/QC plan is permissible, provided that the information can be made available in hardcopy upon request during an audit. Daily Calibration Error (CE) Test: Conduct daily CE testing of each gas monitoring system according to the procedures in Section 6.3.1 of 40 CFR pt. 75, Appendix A and of each flow monitoring system according to the procedures in Section 6.3.2 of 40 CFR pt. 75, Appendix A. Linearity and Leak Check Test (Acid Rain Program): due before the end of each QA operating quarter (calendar quarter in which there are at least 168 unit operating hours) following Permit Issuance in accordance with procedures in 40 CFR pt. 75, Appendix B, Sections 2.2.1 and 2.2.2, and Appendix A, Section 6.2. Perform a leak check at least once during each QA operating quarter and no less than 30 days apart. CEMS Relative Accuracy Test Audit (RATA): Due semianually following Permit Issuance, i.e., once every two successive QA operating quarters (calendar quarter in which there are at least 168 unit operating hours). Conduct a RATA on all CEMS required by the Acid Rain Program, in accordance with 40 CFR pt. 75, Appendix B. Relative accuracy test audits may be performed annually (i.e., once every four successive QA operating quarters, rather than once every two successive QA operating quarters) if any of the conditions listed in 40 CFR pt. 75, Appendix B, Sections 2.3.1.2(a) through 2.3.1.2(i) are met. Quarterly Reports: Electronically report the data and information in 40 CFR Section 75.64 (a), (b), and (c) to the Administrator quarterly. Recordkeeping: The owner or operator shall maintain for each affected unit a file of all measurements, data, reports, and other information required by this part at the source in a form suitable for inspection for at least three (3) years from the date of each record. The file shall contain all information required by 40 CFR Section 75.57. Why to do it 40 CFR Sections 75.20(a)(2), 75.60(b)(1), & 75.63 40 CFR Section 75.10(d)(1) 40 CFR Section 75.21 40 CFR pt. 75, Appendix B, Section 1 40 CFR pt. 75, Appendix B, Section 2.1 40 CFR pt. 75, Appendix B, Sections 2.2.1 & 2.2.2 40 CFR pt. 75, Appendix B, Section 2.3.1 40 CFR Section 75.64 40 CFR Section 75.57

TABLE A: LIMITS AND OTHER REQUIREMENTS Facility Name: Hutchinson Utilities Commission -Plant 2 Permit Number: 08500034-002 A-13 Subject Item: Associated Items: MR 002 CO2 monitor CM 002 Acid Rain Monitoring EU 001 Main turbine, single and combined cycles What to do The CEMS/COMS requirements listed below outline the typical standards of 40 CFR Pt. 75. Additional monitoring requirements may also apply to the Facility based on the standard and it is the responsibility of the Facility to meet all applicable requirements. Certification Application: The owner or operator shall apply for certification of each continuous emission or opacity monitoring system used under the Acid Rain Program. The owner or operator shall submit the certification application in accordance with 40 CFR Section 75.60 and each complete certification application shall include the information specified in Section 75.63. Monitoring Data: Hourly averages shall be computed using at least one data point in each fifteen minute quadrant of an hour, where the unit combusted fuel during that quadrant of an hour. Not withstanding this requirement, an hourly average may be computed from at least two data points separated by a minimum of 15 minutes (where the unit operates for more than one quadrant of an hour) if data is unavailable as a result of the performance of calibration, quality assurance, or preventive maintenance activities pursuant to 40 CFR Section 75.21 and appendix B of pt. 75, or backups of data from the data acquisition and handling system, or recertification, pursuant to Section 75.20. The owner or operator shall use all valid measurements or data points collected during an hour to calculate the hourly averages. All data points collected during an hour shall be, to the extent practicable, evenly spaced over the hour. CEMS QA/QC: The owner or operator of an affected facility shall operate, calibrate, and maintain each CEMS according to the QA/QC procedures in 40 CFR pt. 75, Appendix B as amended. QA Plan: Develop and implement a written plan that describes in detail (or that refers to separate documents containing) complete, step-by-step procedures and operations of the activities outlined in 40 CFR pt. 75, Appendix B, Section 1.1. Upon request from regulatory authorities, the source shall make all procedures, maintenance records, and ancillary supporting documentation from the manufacturer (e.g., software coefficients and troubleshooting diagrams) available for review during an audit. Electronic storage of the information in the QA/QC plan is permissible, provided that the information can be made available in hardcopy upon request during an audit. Daily Calibration Error (CE) Test: Conduct daily CE testing of each gas monitoring system according to the procedures in Section 6.3.1 of 40 CFR pt. 75, Appendix A and of each flow monitoring system according to the procedures in Section 6.3.2 of 40 CFR pt. 75, Appendix A. Linearity and Leak Check Test (Acid Rain Program): due before the end of each QA operating quarter (calendar quarter in which there are at least 168 unit operating hours) following Permit Issuance in accordance with procedures in 40 CFR pt. 75, Appendix B, Sections 2.2.1 and 2.2.2, and Appendix A, Section 6.2. Perform a leak check at least once during each QA operating quarter and no less than 30 days apart. CEMS Relative Accuracy Test Audit (RATA): Due semianually following Permit Issuance, i.e., once every two successive QA operating quarters (calendar quarter in which there are at least 168 unit operating hours). Conduct a RATA on all CEMS required by the Acid Rain Program, in accordance with 40 CFR pt. 75, Appendix B. Relative accuracy test audits may be performed annually (i.e., once every four successive QA operating quarters, rather than once every two successive QA operating quarters) if any of the conditions listed in 40 CFR pt. 75, Appendix B, Sections 2.3.1.2(a) through 2.3.1.2(i) are met. Quarterly Reports: Electronically report the data and information in 40 CFR Section 75.64 (a), (b), and (c) to the Administrator quarterly. Recordkeeping: The owner or operator shall maintain for each affected unit a file of all measurements, data, reports, and other information required by this part at the source in a form suitable for inspection for at least three (3) years from the date of each record. The file shall contain all information required by 40 CFR Section 75.57. Why to do it 40 CFR Sections 75.20(a)(2), 75.60(b)(1), & 75.63 40 CFR Section 75.10(d)(1) 40 CFR Section 75.21 40 CFR pt. 75, Appendix B, Section 1 40 CFR pt. 75, Appendix B, Section 2.1 40 CFR pt. 75, Appendix B, Sections 2.2.1 & 2.2.2 40 CFR pt. 75, Appendix B, Section 2.3.1 40 CFR Section 75.64 40 CFR Section 75.57